I'm a relative new user of FG. My group and I did the comparison between Roll20 and FG and decided to go with FG. What I love, love, love about FG is the automation. It really does a lot of the work for you but there is a bit of a learning curve. I did watch a bunch of YouTube videos and from that, it gave me a pretty good foundation. There's been a bunch of posts here on EN World about the two of them also. A couple of links with some good information:
http://www.enworld.org/forum/showth...sy-Grounds-Roll20-or-both/page2#ixzz4V2qDkCK5
http://www.enworld.org/forum/showthread.php?464064-Roll20-or-Fantasy-Grounds/page3#ixzz4V2uVXfdn
A YouTube link comparing the two (it helped but is more favorable to FG so take that with a grain of salt):
https://www.youtube.com/watch?v=qb-d3Zcznj4
Some high level highlights from those first two posts that I got from it (not my words but lifted straight from a post):
Roll20s strengths are in my experience -
* the free option (though its not really free - you are being subsidised by those who are paying the subs - they stop paying and join the ranks of free users and then the service stops) is hard to beat
* dynamic lighting, this is not available in Fantasy Grounds and probably wont be for at least another 12 months
* better dice macros, you can build exploding and keep and reroll dice pools easier in roll20, this is likely to still be the situation for another 12 months
* integrated video client, whilst video is not for everyone - being able to *see* who is speaking and their Char name is handy
* no firewalls to setup which a Fantasy Grounds GM does have to do - mind you Roll20 also blue screens my computer if I use Chrome and not Firefox so it aint all plain sailing!
I have played a lot of sessions on Fantasy Grounds and have purchased several DLC packages including 5e.
Fantasy Grounds strengths are in my experience -
* outright purchase option is much cheaper than an ongoing subscription - but the subscription option is there also
* GM prep is so much easier on Fantasy Grounds
* pins on maps is just such an intuitive way to prep your campaigns
* encounter setup makes game play so much smoother and cooler
* effects for those rulesets that support them (like 5e/4e/3.5e/PF in particular) are just amazing
* the system supports things like damage reduction, resistance, immunity to specific damage types - eg skeleons and piercing/slashing/bludgeoning weapons, creatures that can only be hit by magic, or fire, or silver, creatures that either resist or take additional damage to damage types like cold, radiant, magic etc
* the core DLC for 5e is just brilliant. its not a character builder - and the main reason for this is because most people house rule *some* aspect of their games so forcing 100% legal builds on you would be limiting - but it does do a good chunk of pointing you in the right direction. full equipment, spells lists. full monsters all statted up. abilities and proficiencies etc.
* the prebuilt modules - Lost Mines of Phandelver, Hoard of the Dragon Queen, Rise of Tiamat and Princes of the Apocalypse are all ready to run. Everything is ready to sit down and play - including the Pre-Gens, Maps, Encounters, Descriptions etc etc.
And contrary to what many people think - you absolutely can play unsupported games on Fantasy Grounds. CoreRPG by itself or with some extensions can support you playing, very effectively, a lot of games that people dont think you can run on Fantasy Grounds.
And community members also create and release community rulesets that add a huge amount of system specific framework and interfaces for other games. Last month a DCC and a ShadowRun 4 ruleset were both made available by community members.
Another system that is very well supported on Fantasy Grounds is Savage Worlds - an awesome ruleset with lots of settings and variants available.
We just ran FGDaze! 2 weeks ago where we (community members) ran a day of one shots aimed squarely at new comers to Fantasy Grounds. We ran 5e, Pathfinder, Star Wars, Maelstrom, ShadowRun, Savage Worlds and more - totally free for everyone to play - even those with only a free/demo license. We will be running another event in August and then FGCon7 will be running in October.
Sorry for the massive text wall. I hope this helps and good luck with your choice!! A VTT has helped me immensely as I now can game with some of my friends that have moved out of town.